journal article·2026-07Open access

Emergent Chaos‐Like Dynamics of Spin–Orbit‐Torque‐Driven Magnetic Transitions

L.‐M. Kern, K. Litzius, V. Deinhart, M. Schneider, C. Klose, K. Gerlinger, R. Battistelli, D. Metternich, D. Engel, C. M. Günther, M.‐J. Huang, K. Höflich, F. Büttner, S. Eisebitt, B. Pfau

Small· Volume 22· Issue 37

Abstract

ABSTRACT Spin–orbit torques (SOTs) are widely used to control magnetization in nanoscale electric systems and are typically assumed to drive skyrmion nucleation and motion in a deterministic manner, especially in materials with strong Dzyaloshinskii–Moriya interaction. Here, using time‐resolved holography‐based x‐ray microscopy supported by micromagnetic simulations, we reveal that on nano‐ to picosecond timescales the actual dynamics can deviate strikingly from this expectation by producing transient regimes of chaos‐like behavior. By exploiting deterministic skyrmion generation at an anisotropy‐engineered defect and implementing a high‐resolution pump–probe scheme, we directly track the magnetization evolution in real space. This approach uncovers a dynamic phase transition that separates coherent SOT‐driven motion from a regime of transient instability characterized by picosecond‐scale fluctuations, strong domain disorder, topological instabilities, and skyrmion shedding, experimentally observed here for the first time. During SOT actuation, the system briefly enters this instability regime, showing short‐lived chaos‐like behavior, yet it reliably relaxes into robust and reproducible final states. Our results demonstrate a powerful methodology for accessing time‐averaged nano‐ to picosecond dynamics in magnetic systems and reveal a previously hidden layer of transient, topologically rich behavior underlying nominally deterministic skyrmion control.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Micro and Nano Robotics · Magnetic properties of thin films · Geomagnetism and Paleomagnetism Studies

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy Berlin Germany

Experimental Physics V, Center for Electronic Correlations and Magnetism University of Augsburg Augsburg Germany

Helmholtz‐Zentrum Berlin für Materialien und Energie Berlin Germany

Ferdinand‐Braun‐Institut (FBH) Berlin Germany

Zentraleinrichtung Elektronenmikroskopie Technische Universität Berlin Berlin Germany

Deutsches Elektronen‐Synchrotron Hamburg Germany

Institut für Optik und Atomare Physik Technische Universität Berlin Berlin Germany

Funding

Leibniz-Gemeinschaft · European Cooperation in Science and Technology

References (48)

Show source-provided references
1. 10.1103/RevModPhys.89.02500610.1103/RevModPhys.89.025006 ↗
2. 10.1109/TMAG.2021.307858310.1109/TMAG.2021.3078583 ↗
3. 10.1038/nnano.2017.15110.1038/nnano.2017.151 ↗
4. 10.1016/j.jmmm.2022.16969210.1016/j.jmmm.2022.169692 ↗
5. 10.1038/s41565-018-0255-310.1038/s41565-018-0255-3 ↗
6. 10.1038/s41565-019-0421-210.1038/s41565-019-0421-2 ↗
7. 10.1126/sciadv.aax846710.1126/sciadv.aax8467 ↗
8. 10.1063/5.000709510.1063/5.0007095 ↗
9. 10.1038/nmat459310.1038/nmat4593 ↗
10. 10.1038/nnano.2017.17810.1038/nnano.2017.178 ↗
11. 10.1021/acs.nanolett.7b0064910.1021/acs.nanolett.7b00649 ↗
12. 10.1038/s42254-021-00302-910.1038/s42254-021-00302-9 ↗
13. 10.1038/nnano.2013.2910.1038/nnano.2013.29 ↗
14. 10.1038/nphys400010.1038/nphys4000 ↗
15. 10.1038/s41928-019-0359-210.1038/s41928-019-0359-2 ↗
16. 10.1073/pnas.250620412210.1073/pnas.2506204122 ↗
17. 10.1038/nphys323410.1038/nphys3234 ↗
18. 10.1126/science.aaa144210.1126/science.aaa1442 ↗
19. 10.1021/acs.nanolett.9b0284010.1021/acs.nanolett.9b02840 ↗
20. 10.1038/ncomms1557310.1038/ncomms15573 ↗
21. 10.1038/s41928-018-0070-810.1038/s41928-018-0070-8 ↗
22. 10.1021/acs.nanolett.1c0013610.1021/acs.nanolett.1c00136 ↗
23. 10.1021/acs.nanolett.2c0067010.1021/acs.nanolett.2c00670 ↗
24. 10.1103/RevModPhys.94.03500510.1103/RevModPhys.94.035005 ↗
25. 10.1021/acs.nanolett.1c0086510.1021/acs.nanolett.1c00865 ↗
26. 10.1021/acs.nanolett.3c0379210.1021/acs.nanolett.3c03792 ↗
27. X.Zhang C.Reichhardt C.Reichhardt Y.Zhou Y.Xu andM.Mochizuki “Asymmetric Diffusion of Chiral Skyrmions ”arXiv Preprint arXiv:2506.14090(2025).
28. 10.1063/5.021526710.1063/5.0215267 ↗
29. 10.1016/j.physb.2017.09.04310.1016/j.physb.2017.09.043 ↗
30. 10.1088/1367-2630/aa856910.1088/1367-2630/aa8569 ↗
31. 10.1063/5.004603310.1063/5.0046033 ↗
32. 10.1002/adma.20180546110.1002/adma.201805461 ↗
33. 10.1063/1.511193710.1063/1.5111937 ↗
34. 10.1021/acs.nanolett.0c0206010.1021/acs.nanolett.0c02060 ↗
35. 10.1364/OPTICA.50599910.1364/OPTICA.505999 ↗
36. 10.1103/PhysRevLett.131.11670110.1103/PhysRevLett.131.116701 ↗
37. 10.1126/science.123015510.1126/science.1230155 ↗
38. 10.1038/ncomms988910.1038/ncomms9889 ↗
39. 10.1103/PhysRevLett.134.15670110.1103/PhysRevLett.134.156701 ↗
40. 10.1098/rsta.2007.211610.1098/rsta.2007.2116 ↗
41. 10.1103/PhysRevApplied.13.03401610.1103/PhysRevApplied.13.034016 ↗
42. 10.1103/PhysRevB.104.05442710.1103/PhysRevB.104.054427 ↗
43. 10.1038/nature0313910.1038/nature03139 ↗
44. 10.3762/bjnano.12.2510.3762/bjnano.12.25 ↗
45. 10.1126/science.280.5371.191910.1126/science.280.5371.1919 ↗
46. 10.1038/s41598-021-02902-y10.1038/s41598-021-02902-y ↗
47. 10.1103/RevModPhys.91.03500410.1103/RevModPhys.91.035004 ↗
48. 10.1063/1.500395710.1063/1.5003957 ↗